摘要
在木论自然保护区极小种群单性木兰(Kmeria septentrionalis)群落木本植物每木调查的基础上,采用混交度、角尺度和大小比数3个林分空间结构参数,分析单性木兰生存群落木本植物物种组成及其空间结构特征。结果表明,样地内共有木本植物树种95种,隶属于55科82属,为典型的阔叶混交异龄林。群落林木以小径级占绝对优势,林木个体随着径级的增大急剧减少,整体呈倒J型分布。群落中大部分树种处于强度混交,树种间混交程度较高,林分平均混交度达0.742;群落林分大小比数为0.508,不同等级的林木在空间结构单元内分布较均匀;大部分林木介于随机分布和不均匀分布,均匀分布比例较少,林分平均角尺度为0.549,群落空间分布格局为轻度聚集分布。单性木兰种群径级结构呈倒J型,种群从幼苗向幼树生长过程中林木个体急剧减少。单性木兰种群混交度为0.796,处于高度混交状态;平均大小比数为0.400,处于亚优势偏向中庸状态;角尺度为0.528,呈轻度聚集分布状态。单性木兰群落不仅亟须有效保护,同时需采取适当的人为干扰措施促进种群的延续与发展。
Three stand spatial structure parameters, including mingling degree, uniform angle and size ratio, were used to analyze species compositions and spatial structure patterns of a rare species Kmeria septentrionalis community in Mulun Reserve, Guangxi. The result showed that the community included 95 woody species, belonging to 55 families, 82 genera, being a typical une- ven-aged mixed broad-leaf forest. The community was dominated by small DBH individuals, and tree numbers decreased as DBH increased, presenting an inverse J shape distribution. In the community, a majority of trees were strongly mingled （with an average mingling degree 0.742）, and the size ratio was 0.508. Trees with hierarchical DBHs were evenly distributed in spatial structure, and most trees were of random to uneven distribution （with an average uniform angle 0.549） , representing a mild aggregation. K. septentrionalis＇ DBH structure also presented an inverse J shape, with decreased individuals in the process from seedlings to young trees. K. septen- trionalis population had high mingling degree （0.796）, moderate size ratio （0.400） and weak aggregated distribution （uniform angle 0.528）. In sum, efficient conservation and appropriate human interference efforts are needed for a sustainable K. septentrionalis population.
出处
《生态学杂志》
CAS
CSCD
北大核心
2016年第2期363-369,共7页
Chinese Journal of Ecology
基金
广西壮族自治区林业厅科技项目(桂林预护2013009)资助
关键词
单性木兰
物种组成
空间分布格局
混交度
大小比数
角尺度
Kmeria septentrionalis
species composition
spatial pattern
mingling degree
size ratio
uniform angle index.
